Prediction Methods for Near Field Noise Environments of VTOL Aircraft

Download or read book Prediction Methods for Near Field Noise Environments of VTOL Aircraft written by Louis C. Sutherland and published by . This book was released on 1972 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report establishes a consistent set of prediction methods which may be used to estimate near field noise levels for jet powered and rotor/propeller powered VTOL aircraft operating in close proximity to the ground. The methods provided utilize available theory augmented extensively by experimental data which was available or was obtained during the program. The noise prediction methods presented will allow an analysis of near field environments of VTOL aircraft using a simplified procedure suitable for manual calculations. The experimental effort carried out in the program consisted of noise measurements in the near field of a model propeller and a subsonic jet in a free and vertical configuration. Ground reflection correction factors for a simple source are tabulated along with the computer program listing. The methods described in this report are intended for use by aircraft designers for the prediction of the near field noise environment of VTOL aircraft as required in MIL A 8893 Airplane Strength and Rigidity, Sonic Fatigue Resistance.